Sleep deprivation impairs activity in the brain’s frontal lobe
This is the part of the brain responsible for complex decision making
Lack of sleep increases activity in the centres that respond to rewards
This means sleep deprived people are more likely to choose junk food
Sleep deprivation can increase cravings for junk food, according to a new university report.
A sleepless night makes us more likely to reach for doughnuts or pizza than for whole grains and leafy green vegetables, the U.S. study suggests.
The study at the University of California, Berkeley, examined the brain regions that control food choices and researchers say the findings shed new light on the link between poor sleep and obesity.
A sleepless night makes us more likely to reach for doughnuts or pizza than for leafy green vegetables
Using functional magnetic resonance imaging (fMRI), researchers scanned the brains of 23 healthy young adults, first after a normal night’s sleep and next, after a sleepless night.
They found impaired activity in the sleep deprived brain’s frontal lobe, which governs complex decision making, but increased activity in deeper brain centres that respond to rewards.
Moreover, the participants favoured unhealthy snacks and junk food when they were sleep deprived.
‘What we have discovered is that high-level brain regions required for complex judgments and decisions become blunted by a lack of sleep, while more primal brain structures that control motivation and desire are amplified,’ said Professor Matthew Walker, a UC Berkeley professor of psychology and neuroscience.
Moreover, he added: ‘High calorie foods also became significantly more desirable when participants were sleep-deprived.
‘This combination of altered brain activity and decision making may help explain why people who sleep less also tend to be overweight or obese.’
There is impaired activity in the sleep deprived brain’s frontal lobe, which governs complex decision making, but increased activity in deeper brain centres that respond to rewards
Previous studies have linked poor sleep to greater appetites, particularly for sweet and salty foods, but the latest findings provide a specific brain mechanism explaining why food choices change for the worse following a sleepless night, Professor Walker said.
‘These results shed light on how the brain becomes impaired by sleep deprivation, leading to the selection of more unhealthy foods and, ultimately, higher rates of obesity,’ said Stephanie Greer, a doctoral student in Professor Walker’s
Sleep and Neuroimaging Laboratory.
In this newest study, researchers measured brain activity as participants viewed a series of 80 food images that ranged from high to low calorie and healthy and unhealthy, and rated their desire for each of the items.
Sleep deprivation contributes to obesity because people who are very tired favour unhealthy snacks and junk food over healthier alternatives
As an incentive, they were given the food they most craved after the MRI scan.
Food choices presented in the experiment ranged from fruits and vegetables, such as strawberries, apples and carrots, to high calorie burgers, pizza and doughnuts.
On a positive note, Professor Walker said, the findings indicate that ‘getting enough sleep is one factor that can help promote weight control by priming the brain mechanisms governing appropriate food choices’.
Read more: http://www.dailymail.co.uk/health/article-2385911/How-insomnia-make-FAT-Scientists-discover-sleep-deprivation-increases-cravings-junk-food.html#ixzz2bRSkATxd
